{{Short description|Family of turboshaft and turboprop engines}} {{more citations needed|date=January 2010}} {{infobox aero engine | name = T700 / CT7 | image = General Electric XT700-GE-700 Turboshaft Engine - DPLA - 36818a2b62bf8af83acbaef7f15ef957 (page 7).jpg | caption = An experimental XT700-GE-700 assembly being preserved at the National Air and Space Museum |manufacturer= GE Aviation |engine_type= Turboshaft |national_origin = United States |first_run= 1973 |major_applications= {{ubl|Bell AH-1W SuperCobra |Bell AH-1Z Viper |Bell UH-1Y Venom |Boeing AH-64 Apache |CASA/IPTN CN-235 |KAI KUH-1 Surion |Saab 340 |Sikorsky UH-60 Black Hawk |Sikorsky SH-60 Seahawk}} |number_built= Over 20,000<ref name="GEReports20191216">{{cite news |work=GE Reports: Future of Flight |title=Stayin' Alive: Trusty GE Chopper Engine That Entered Service When The Bee Gees Ruled The Charts Wins New $1 Billion Lease On Life |url=https://www.ge.com/news/reports/stayin-alive-trusty-ge-chopper-engine-that-entered-service-when-the-bee-gees-ruled-the-charts-wins-new-1-billion-lease-on-life |date=December 16, 2019 |given1=Amy |surname1=Kover |given2=Tomas |surname2=Kellner |access-date=May 15, 2021}}</ref> |developed_from= |variants_with_their_own_articles= |developed_into=General Electric T901 }}

The '''General Electric T700''' and '''CT7''' are a family of turboshaft and turboprop engines in the {{convert|1500|-|3000|shp|abbr=on}} class.

==Design and development== In 1967, General Electric began work on a new turboshaft engine demonstrator designated the "GE12" in response to US Army interest in a next-generation utility helicopter.<ref name="HistoryBook">{{cite book|last1=Leyes|first1=Richard A.|last2=Fleming|first2=William A.|title=The History of North American Small Gas Turbine Aircraft Engines|date=1999|publisher=AIAA|isbn=9781563473326|url=https://books.google.com/books?id=V0SnFt8JGokC&q=%221967%22+%2B+%22GE12%22+engine&pg=PA329|access-date=5 October 2017}}</ref> The GE12 was designed and conceived by GE's Art Adamson and Art Adinolfi. In 1967, both GE and Pratt & Whitney were awarded contracts to work parallel with each other to design, fabricate, and test the technology.<ref name="HistoryBook"/> The Army effort led, in the 1970s, to development of the Sikorsky S-70 Black Hawk, powered by twin GE "T700" turboshafts, the production descendant of the GE12.<ref name="HistoryBook"/>

The T700 was initially bench-tested in 1973, passed military qualification in 1976, and went into production in 1978.<ref>{{cite web|title=Unknown Title|url=https://books.google.com/books?id=60FWAAAAMAAJ&q=%221973%22+%2B+%22T700%22+engine+bench+tested|website=Verti-flite, Volume 37|year = 1991|access-date=5 October 2017}}</ref> The initial "T700-GE-700" is an ungeared free-turbine turboshaft, with a five-stage axial / one-stage centrifugal mixed-flow compressor, featuring one-piece "blisk" axial stages, with the inlet guide vanes and first two stator stages variable; an annular combustion chamber with central fuel injection to improve combustion and reduce smoke; a two-stage compressor turbine; and a two-stage free power turbine with tip-shrouded blades. The engine is designed for high reliability, featuring an inlet particle separator designed to spin out dirt, sand, and dust. The T700-GE-700 is rated at 1,622 shp (1,210&nbsp;kW) intermediate power.

The T700-GE-700 was followed by improved and uprated Army engine variants for the UH-60 Black Hawk and the AH-64 Apache helicopters, as well as marinized naval engine variants for the SH-60 Seahawk derivative of the Black Hawk, the SH-2G Seasprite, and the Bell AH-1W Supercobra. T700s are also used on Italian and commercial variants of the AgustaWestland EH101/AW101 helicopter, and Italian variants of the NHIndustries NH90 helicopter. These are all twin-engine machines, except for the three-engined EH101.

The commercial version of the T700 is the "CT7", with the engine used on the Bell 214ST (an enlarged version of the Huey), commercial Black Hawks, and the Sikorsky S-92 derivative of the Black Hawk, all of which are twin-engine helicopters.

The CT7 turboprop variants use the same core as the turboshaft variants, with a propeller gearbox fitted forward of the core. CT7 turboprops are used on variants of the Swedish Saab 340 airliner, the Indonesian-Spanish Airtech CN-235 cargolifter, and the Czech Let L-610G airliner, all twin-turboprop aircraft. The baseline CT7-5A provides 1,735 shp (1,294&nbsp;kW) on takeoff.

In the late 1980s, GE also proposed a much larger turboprop, the T407/GLC38, with a five-stage axial/one-stage centrifugal mixed-flow compressor, an annular combustor with 15 burners; a two-stage compressor turbine, a three-stage power turbine, and max takeoff power of 6,000 shp (4,475&nbsp;kW).

The YT706 engine is based on the CT7-8A engine. Compared with the H-60's primary T700 engine, the T706 has a larger compressor, hot section improvements, and full authority digital engine control.<ref name="YT706">{{cite web |url=http://www.geae.com/aboutgeae/presscenter/military/military_20070813.html |title=GE YT706 Production Contract Awarded by US Army |access-date=2007-08-16 |date=2007-08-13 |publisher=GE Aviation |url-status=dead |archive-url=https://web.archive.org/web/20071023113512/http://www.geae.com/aboutgeae/presscenter/military/military_20070813.html |archive-date=2007-10-23 }}</ref> The T706 is rated at 2,600&nbsp;shp (1,939&nbsp;kW) and increases the hot-and-high mission capability of the U.S. Army's MH-60M Black Hawk for Special Operations applications.<ref name=Janes_S-70>[https://janes.ihs.com/Janes/Display/1343474 "Sikorsky S-70A."] (online subscription article) ''Jane's All the World's Aircraft'', 25 May 2016.</ref>

==Variants== [[File:Maintenance on GE T700 engine aboard USS Bonhomme Richard (LHD-6) in March 2015.JPG|thumb|US Marines perform maintenance on the T700-GE-401C from a Bell UH-1Y helicopter]]

'''T700''': Military turboshaft engine. *'''YT700''': Prototype version. *'''T700-GE-700''': Initial T700 variant. *'''T700-GE-701''': The improved T700-GE-701A, -701B, -701C,-701D versions have also been developed from the original -700.<ref>{{Cite web |url=http://www.usarmyaviation.com/studyguides/index.php?folder=Documents%2FUH-60BlackhawkSpecific%2FEngine&download=Engine.ppt |title=The General Electric T-700/T-701C |access-date=2022-07-09 |archive-date=2014-05-02 |archive-url=https://web.archive.org/web/20140502002320/http://www.usarmyaviation.com/studyguides/index.php?folder=Documents/UH-60BlackhawkSpecific/Engine&download=Engine.ppt |url-status=dead }}</ref> *'''T700-GE-401''': Navalised version for SH-60 Seahawk helicopters. *'''T700-GE-401C''': Universal application version of the -401. *'''T700-GE-701C''': Universal application version of the -701. *'''T700-TEI-701D''': Licensed produced version of Tusaş Engine Industries of Turkey. Developed for use in the Sikorsky/Turkish Aerospace Industries T-70 utility helicopter.<ref>{{cite web|url=https://www.tei.com.tr/sayfalar/modul/params/tip-haber/id-51/anamenuid-44/TEI%2520TO%2520POWER%2520BLACKHAWKS.html#gorselW:179/gorselH:134|title=TEI TO POWER BLACKHAWKS {{!}}|website=www.tei.com.tr|access-date=2016-09-17|archive-url=https://web.archive.org/web/20160919202637/https://www.tei.com.tr/sayfalar/modul/params/tip-haber/id-51/anamenuid-44/TEI%2520TO%2520POWER%2520BLACKHAWKS.html#gorselW:179/gorselH:134|archive-date=2016-09-19|url-status=dead}}</ref> *'''T700-701K''': First rear-drive version of the T700 family, a product from the joint development with Samsung Techwin (later became Hanwha Aerospace). Powering the KAI KUH-1 Surion with Hanwha's licensed production.<ref>{{Cite web |title=T700-701K turboshaft engines datasheet |url=https://www.geaerospace.com/sites/default/files/datasheet-T700-701K.pdf |website=GE Aerospace}}</ref>

'''CT7 turboshaft''': Commercial version of T700. *'''CT7-2A''': Basic model *'''CT7-2D''': Higher flow compressor and surface coatings to improve resistance to wear and corrosion *'''CT7-2D1''': Similar to the CT7-2D but uses a CT7-6 type hot section *'''CT7-2E1''': Leonardo Helicopters AW189 *'''CT7-6/-6A''': The CT7-6/-6A turboshaft engines are upgraded commercial variants of the successful T700/CT7 engine family. The turboshaft engine powers the entire development fleet of AgustaWestland AW101 helicopters with thousands of flight hours of operation.<ref name="geaviation.com">{{cite web|url=https://www.geaviation.com/commercial/engines/ct7-engine|title=The CT7 Engine - GE Aviation|website=www.geaviation.com}}</ref> *'''CT7-8''': The CT7-8 is a family of powerful engines in the 2,500 to 3,000 shp class. They are more powerful and more efficient versions of its predecessors.<ref name="geaviation.com"/> *'''CT7-8A''': A version of the CT7-8 family used to power older Sikorsky S-92/H-92 helicopters. *'''CT7-8A1''': A more fuel efficient version of the CT7-8A. It is used to power newer Sikorsky S-92/H-92 helicopters. The CT7-8A1 produces 2,520 shp. *'''CT7-8A5''' *'''CT7-8A7''': Developed by GE as an uprated, more efficient and more reliable version of the CT7-8A1 engine for the Royal Canadian Air Force's Sikorsky CH-148 Cyclone helicopters. It is the most modern version of the CT7/T700 engine family. The CT7-8A7 produces 3,000 shp. *'''CT7-8B''' *'''CT7-8B5''' *'''CT7-8E''' *'''CT7-8E5''' *'''CT7-8E6''' *'''CT7-8F''' *'''CT7-8F5'''

'''CT7 turboprop''': Turboprop version of CT7. *'''CT7-3''': Compact shortened and lightened version.<ref name=JAWA88-89>{{cite book |title=Jane's All the World's Aircraft 1988-89 |year=1988 |publisher=Jane's Information Group |location=London |isbn=0-7106-0867-5 |editor=John W.R. Taylor}}</ref> *'''CT7-5A2''' *'''CT7-5A3''' *'''CT7-7A''' *'''CT7-7A1''' *'''CT7-9B''' *'''CT7-9B1''' *'''CT7-9B2''' *'''CT7-9C''' *'''CT7-9C3''' *'''CT7-9D''' *'''CT7-9D2'''

==Applications== thumb|A U.S. Navy Sailor performing maintenance on a T700 engine from a MH-60R Sea Hawk. [[File:T700-IHI-401C2 turboshaft Engine air intake of JMSDF SH-60K(8430) right front view at Maizuru Air Station July 29, 2017.jpg|thumb|An T700-IHI-401C2 being mounted on a Japanese SH-60K]]

===T700/CT7 turboshaft=== * AgustaWestland AW101 ** AgustaWestland CH-149 Cormorant ** Lockheed Martin VH-71 Kestrel * AgustaWestland AW149 * AgustaWestland AW189 * Bell 214ST * Bell 525 * Bell AH-1W SuperCobra * Bell AH-1Z Viper * Bell UH-1Y Venom * Boeing AH-64 Apache * KAI KUH-1 Surion * Kaman SH-2G Super Seasprite * Kamov Ka-64 Sky Horse * Leonardo Helicopters AW249 * NHIndustries NH90 * Sikorsky S-70/H-60 series ** Mitsubishi H-60 ** Piasecki X-49 ** Sikorsky HH-60 Jayhawk ** Sikorsky HH-60 Pave Hawk ** Sikorsky SH-60 Seahawk ** Sikorsky UH-60 Black Hawk * Sikorsky S-92 ** Sikorsky CH-148 Cyclone

===YT706 turboshaft=== * Sikorsky MH-60M Black Hawk * Sikorsky S-97 Raider

===CT7 turboprop=== * CASA/IPTN CN-235 * Let L-610G * Saab 340 * Sukhoi Su-80

==Specifications (T700)== {{jetspecs <!-- If you do not understand how to use this template, please ask at Wikipedia talk:WikiProject Aircraft. Please include units where appropriate (main comes first, alt in parentheses). If data are missing, leave the parameter blank (do not delete it). For additional lines, end your alt units with )</li> and start a new, fully-formatted line with <li> --> |type=Turboshaft engine |length= {{convert|47|in|abbr=on}} (T700-GE-700/701 series); {{convert|48.2|in|abbr=on}} (T700/T6A) |diameter={{convert|25|to|26|in|abbr=on}} (T700/T6E) |weight=<br /> **{{convert|400|lb|abbr=on}} (YT700-GE-700) **{{convert|437|lb|abbr=on}} (T700-GE-700) **{{convert|537|lb|abbr=on}} (T700/T6E) |compressor=6 stage-5 stage axial, 1 stage centrifugal. |combustion=Annular |turbine=2 stage gas generator and 2 stage power turbine |fueltype= JP-4 or JP-5 (YT700-GE-700) |oilsystem=Self contained, pressurized, recirculating dry sump |power=<br /> **YT700-GE-700: {{Convert|1,536|shp|kW|0|abbr=on|lk=on}}<ref>Govt Competitive Test UTTAS YUH-60A, USAAEFA Proj # 74-06-1</ref> **T700-GE-700: {{Convert|1,622|shp|kW|0|abbr=on}} **T700/T6E: {{Convert|2,380|shp|kW|0|abbr=on}} **YT706-GE-700: {{Convert|2,638|shp|kW|0|abbr=on}}<ref name="YT706 HP">{{cite web |url=http://geae.com/engines/military/yt706/index.html |title=GE YT706 Power Specifications |publisher=GE Aviation |access-date=2011-06-02 |archive-url=https://web.archive.org/web/20110614052527/http://www.geae.com/engines/military/yt706/index.html |archive-date=2011-06-14 |url-status=dead }}</ref> |thrust= |compression=17:1 |aircon= |turbinetemp= |fuelcon= |specfuelcon={{cvt|0.433|lb/hph|g/kWh}}<ref>{{cite conference |work=Global Research |title= GE turbines and small engines overview |publisher=General Electric |url= https://arpa-e.energy.gov/sites/default/files/14_deBock_GE%20Turbines%20and%20small%20engines%20overview%20-%20ARPA-e%20INTEGRATE%20V2.pdf |conference-url= https://arpa-e.energy.gov/2019-integrate-annual-meeting |author= Peter deBock |conference= ARPA-e INTEGRATE meeting |date= September 18, 2019}}</ref> (T700/T6E) to {{cvt|0.465|lb/hph|g/kWh}} (T700-GE-701A){{cn|date=December 2022}} |power/weight=<br /> **{{convert|3.84|shp/lb|kW/kg|abbr=on}} (YT700-GE-700) **{{convert|3.71|shp/lb|kW/kg|abbr=on}} (T700-GE-700) **{{convert|4.48|shp/lb|kW/kg|abbr=on}} (T700/T6E) |thrust/weight= }}

==See also== {{Aircontent |see also= * Advanced Affordable Turbine Engine, a program to develop a replacement for the T700 engine |related= * General Electric T901 |similar engines= |lists= * List of aircraft engines }}

==References== {{Reflist}}

* {{cite report |title=Type Certificate Data Sheet No. E8NE |url=https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/2b13feaafbaf9629862585c00069c791/$FILE/E8NE_Rev39.pdf |number=39 |author=U.S. Department of Transportation (USDOT), Federal Aviation Administration (FAA) |publication-date=July 20, 2020 |access-date=July 20, 2021 |archive-date=July 16, 2021 |archive-url=https://web.archive.org/web/20210716074246/https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/2b13feaafbaf9629862585c00069c791/$FILE/E8NE_Rev39.pdf |url-status=dead }}

{{vectorsite}}

==External links== {{Commons category}} * [https://web.archive.org/web/20110516062546/http://www.geae.com/engines/military/t700/index.html General Electric T700/CT7 Engine Family page on GE Aviation site] * [http://www.faqs.org/docs/air/v2003m10.html Jet Engines by Greg Goebel on faqs.org] * [http://www.flightglobal.com/airspace/photos/aeroenginesjetcutaways/general-electric-ge-ct7-cutaway-5607.aspx General Electric CT7 Cutaway by FlightGlobal.com]

{{GE aeroengines}} {{USAF gas turbine engines}}

T700 Category:1970s turboshaft engines